(CNET) -- San Mateo County prosecutors are defending the search of a Gizmodo.com editor's home and seizure of his computers that are part of a criminal investigation into an iPhone prototype lost by an Apple employee.

Stephen Wagstaffe, chief deputy district attorney, told CNET on Tuesday evening that prosecutors had considered whether reporter shield laws applied to the search and seizure aimed at the gadget blog -- and decided to proceed after carefully reviewing the rules.

"My prosecutor who is handling it considered this issue right off the bat when it was being brought into him and had some good reasons why he and the judge felt the warrant was properly issued," Wagstaffe said.

Gizmodo's parent company, Gawker Media, has said that the search warrant is "invalid," citing a California law curbing newsroom searches. So has the Electronic Frontier Foundation. However, if Gizmodo employees are targets of the criminal investigation themselves, it's likely that the law's protections do not apply.

Wagstaffe said that if police had delayed, evidence could have been lost.

"I think the people who are saying, 'No, we should have waited' and did it the other way first don't understand that in the world when you're investigating crimes, evidence sometimes gets deleted and destroyed," he said. "If you sit there and work by the Marquess of Queensberry rules, then bad guys win."

Investigators with the San Mateo County Sheriff's office searched the Fremont, Calif., home of Jason Chen last Friday evening. CNET was the first to report, a few hours earlier, that Apple had contacted police and a criminal investigation was under way. Among the items seized were three Apple laptops, a Seagate 500 GB external hard drive, USB flash drives, and an HP MediaSmart server.

"Initially it's just a theft investigation," Wagstaffe said. "But ultimately could it lead to more? That's going to depend on what they learn. That's why they would like to be able to look at the computer and interview everybody that they can so they can determine the extent of what's involved." (Prosecutors have voluntarily agreed not to search Chen's computers while discussing the matter with Gizmodo's lawyer.)

Disclosure of the search warrant has had a polarizing effect in legal and technological circles, with responses ranging from incredulity that police would pursue this case to astonishment that bloggers believed it was acceptable to buy almost-stolen property.

"If you're investigating a crime and you want information from a journalist's news-gathering materials, that is one thing you can do and one thing only, and that's serve a subpoena," said Lucy Dalglish, executive director of the Reporters Committee for Freedom of the Press. "And then when you serve a subpoena, the journalist has the ability to go court and fight it."

An attorney for Gawker Media told CNET on Tuesday that if Gizmodo had been contacted before the search, it would have offered a formal written agreement not to delete any data.